AN36.1-7 | Mouth, Pharynx & Palate — Summary & Reflection

REFLECT

A 12-year-old boy from rural Tamil Nadu is brought with a 4-day history of severe throat pain, inability to open his mouth fully, and a "hot potato" voice. On examination, there is bulging of the right anterior pillar and the uvula is deviated to the left. Temperature is 39.2°C.

What is the diagnosis? What are the anatomical boundaries of the abscess? Which vessels are at risk if the abscess is not drained? Describe the technique of incision and drainage — where exactly do you incise? What is the risk if the abscess tracks laterally into the parapharyngeal space?

KEY TAKEAWAYS

Mouth, Pharynx & Palate — Key Points:

1. Oral cavity: parotid duct opens opposite upper 2nd molar; submandibular duct opens at sublingual papilla; tongue sensation = V3 (anterior 2/3 general) + VII via chorda tympani (taste); CN XII motor
2. Soft palate muscles: tensor (V3) opens Eustachian tube; levator (X) elevates palate (main velopharyngeal closure muscle); uvular deviation to opposite side in unilateral CN X palsy
3. Palatine tonsil: most dangerous relation = ICA (2.5 cm lateral); blood supply = tonsillar artery (branch of facial); tonsillectomy plane = peritonsillar space; paratonsillar vein is main bleeding source
4. Pharyngeal muscles: all constrictors and palatal muscles = CN X via pharyngeal plexus EXCEPT stylopharyngeus (CN IX) and tensor veli palatini (V3)
5. Waldeyer's ring: pharyngeal tonsil + tubal + palatine + lingual; most common site of extranodal lymphoma H&N
6. Pharyngeal spaces: parapharyngeal (lateral to pharynx; ICA inside); retropharyngeal (→ danger space → mediastinum)
7. Pyriform fossa: internal laryngeal nerve in mucosa; site of foreign body lodgement; sinus fistula = left neck abscess in children
8. Killian's dehiscence: between thyropharyngeus and cricopharyngeus; Zenker's diverticulum herniates here → regurgitation of undigested food